Bridge plugs are commonly used to isolate sections of a well, particularly where pressure differentials will result from perforating or drilling in a number of hydrocarbon formations along the well bore. These plugs can also be used to block off well bores which are no longer in use.
Retrievable bridge plugs are generally run downhole to a desired depth using a setting tool. The plugs can be run on electric lines, hydraulic lines, and solid wire lines and are set in position, for example, with an electric wireline setting assembly. The bridge plug can be retrieved using a retrieving tool on a slick line, branded line, coiled tubing or other means.
Bridge plugs generally in use today have a number of disadvantages. They are not adapted for easy use with smaller diameter tubing. When the bypass valve is released to equalize any pressure differential and clear debris in the tubing, the bridge plug also releases. Also, they require at least two trips with a running tool to release and retrieve the plug. This results in a substantial increase in the cost and man hours required to utilize the plug.